In recent years researchers from diverse disciplines in the life sciences have turned their attention to the issue of developmental stability in the organism. Their key measure, fluctuating asymmetry (FA), is defined as the random, stress‐induced deviations from perfect symmetry that develop during the development of bilaterally symmetrical traits. This is regarded as a promising measure of the stress experienced by individuals during their development, as well as the interaction between genetic and environmental forces which affect that development. FA also sheds light on several domains within psychological research, such as the interplay between nature and nurture during human development, etiology of mental health, mating and choice of partners, and even perception of facial beauty. This study reviews the manifestation and sources of FA in humans, and seeks to provide some insight regarding their relevance and possible application to various domains in psychology.